hi occam, i think you may be reading a bit into my words.
occam Wrote: > Dorkus, > He nor I made any mention of ps decoupling of digital circuitry, only a > reference to his rather well chosen (IMO) analog ps. > ??? but in this case the PS is powering the SB, thereby making this a digital application. granted there is a degree of isolation provided by upstream regulation and decoupling, but it is a dB reduction, not a total decoupling of circuits. the PS is part of a digital system, period. > Neither he nor I advocated replacing a smt ceramic for digital > decoupling with a stacked film leaded cap. Why in heaven's name would > you think we'd done so? > i didn't. > Similarly, while I do like the Panny FM electrolytics, as they're > readily available, from objective criteria, I can't see why they'd be > prefferable to Rubycon ZAs. > i never said they were. mamsterla said "I usually use a triple cap in my PS caps - a low ESR like a *Panasonic FC* or a Rubicon ZA/ZL..." i was suggesting trying the Pana FM in place of the FC, since it is a newer improved version. > I'm eagerly awaiting your offer of a smt based external linear supply... i'm not sure why you think i am advocating a different power supply, when i am really trying to offer an alternate perspective on power supply decoupling within the current context. > PS - Thanks for the nerdy references, but save for that 1st general > reference, it might be beneficial to make them relevant to the subject > at hand, decoupling of LINEAR (PS)circuits. they are certainly relevant, as they pertain to supply bypassing in HIGH SPEED DIGITAL applications. the choice of a capacitor in a linear power supply *is* dependent on what it is powering, because the load will modulate the supply line and thus introduce certain frequency components into the system as a whole. this means if you are using a "low-speed" linear analog PS to power a high-speed digital circuit, you must consider the PS to be operating in a high-speed regime now, at least to some extent. i think a common mistake tweakers make is to look at different parts of a circuit or device in isolation, when really the entire beast must be analyzed holistically. this means everything from the power outlet to the RCA jacks - power cords, transformer choice, etc. yes, it would even include the power lines from the electric plant to your house, but we don't have any control over that so of course it's moot. we do what we can with the things that are within our control and are an effective use of time and effort. related to this is the misconception of what i consider "holy grail" parts - magical drop-in replacements which will invariably improve the performance of anything they're installed in. black gates, designer film caps, vishay resistors, OPA627 opamps, you name it. i too have gone down this route in the past, but with experience i've learned there is no such thing as the perfect part for every job. i have heard some great-sounding gear using pedestrian parts which actually didn't sound better when modded with expensive tweak parts, in fact oftentimes they sounded worse. careful component selection is about more than picking what you perceive to be the best individual parts. again, i am not saying your preferred film cap does not work here - i am merely suggesting that there is a *chance* that it may not be wise here, and one should not be so complacent as to assume it will always work. just give the PS a try with and without the film cap, and see what you like better - you could very well hear no difference, or i could be completely wrong and you may like it better with it. but there's arguments either way, and you'll never know for sure until you experiment. -- dorkus ------------------------------------------------------------------------ dorkus's Profile: http://forums.slimdevices.com/member.php?userid=3373 View this thread: http://forums.slimdevices.com/showthread.php?t=19822 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
